A multi-layered film defect may form as a defect inherent to a reflection type mask (EUV exposure mask) used for exposure when using extreme ultraviolet rays (EUV rays). The multi-layered film defect occurs due to a pit or bump on a substrate or foreign matter attached onto the substrate before formation of the multi-layered film or during formation of the film. If the above foreign matter is present, the uniform arrangement of the multi-layered film is disturbed to cause a phase difference with respect to a normal portion. That is, a so-called topological defect occurs.
It is difficult to correct the multi-layered film itself when the topological defect is corrected. Therefore, it is proposed to correct an absorber pattern in order to correctly transfer a pattern. However, in the case of a large topological defect, it is impossible to make a mask correction to correctly transfer the pattern on the wafer simply by correcting the absorber pattern. In this case, it is necessary to attempt to form a non-defective mask again. However, mask reformation is not realistic in many cases in view of the cost and TAT (Turn Around Time).
Further, a method is provided for utilizing the fact that there is substantially no possibility that a defect is present on a first mask and a defect occurs in the same portion of a second mask and transferring a pattern by use of the two masks with the same pattern at the wafer exposure time. Also, a method for arranging a plurality of chips in the same mask and performing double exposure is provided. However, with the above methods, it is necessary to form the same mask or the same chip pattern and the cost for mask formation rises. Additionally, it is predicted that a portion having no defect and formed in a pattern form by double exposure and a portion formed in a pattern form by single exposure because of the presence of a defect in any mask or chip pattern will differ in the transfer pattern dimension.